Computation grid is the infrastructure for the next generation internet. In the past five years, research ongrid technology has been thriving and grid technology has been widely adopted by a number of government organ...Computation grid is the infrastructure for the next generation internet. In the past five years, research ongrid technology has been thriving and grid technology has been widely adopted by a number of government organiza-tions and research institutions to establish their own large-scale resource sharing network. This paper presents a re-view of recent research on elemental grid technology. We focus on a brief overview on Grid's protocol architecture. Inthe end, we list a series of large projects to illustrate the current application situation based on the ongoing grid tech-nology and preview the tendency of grid technology in the future.展开更多
针对无线传感器网络占空比MAC协议在链路或节点失效环境下易导致严重的能量浪费问题,提出了一种基于Grid Quorum的异步低占空比M AC协议-AGQ-M AC(Asynchronous Grid Quorum M AC).AGQ-M AC采用Grid Quorum组分配信道,通过动态调配Quoru...针对无线传感器网络占空比MAC协议在链路或节点失效环境下易导致严重的能量浪费问题,提出了一种基于Grid Quorum的异步低占空比M AC协议-AGQ-M AC(Asynchronous Grid Quorum M AC).AGQ-M AC采用Grid Quorum组分配信道,通过动态调配Quorum比率得到了节点的最优占空比,并在邻节点发现过程中采用双前导序文抽样来监测信道状态,以减少节点唤醒时间从而达到能量高效.仿真实验结果表明,与其他占空比MAC协议相比,AGQ-MAC延长了网络生存时间,降低了网络能耗,提高了邻发现数据传输率,同时保持较低的平均邻发现延迟.展开更多
In recent years,along with the rapid expansion of power grids,the increasing complication of grid structures,and the development of smart grids and energy technologies,the lightning protection of power grids becomes i...In recent years,along with the rapid expansion of power grids,the increasing complication of grid structures,and the development of smart grids and energy technologies,the lightning protection of power grids becomes increasingly prominent.Power grids of China have acquired significant achievements on lightning protection technologies,which are reviewed in this paper.A technical route of lightning protection is introduced in detail; it allows us to find problems through detection and measurement of lightning,to analyze problems through evaluation and simulation of lightning,to solve problems through lightning protection measures,and to prevent problems through hazard risk warning of lightning.Following the route,the technical breakthroughs of these four aspects in China are presented,including the chinese lightning detection network(CLDN),natural lightning observations,lightning faults detection at transmission lines,lightning current measurements,progresses in lightning distribution maps,lightning fault replays,lightning hazard risk evaluations,and lightning simulated experiments,as well as novel lightning protection measures.The practical devices and systems corresponding to the technologies mentioned above are also introduced and discussed.Due to the progress of lightning protection technologies in recent years,despite the rapidly growing length of transmission lines in China,the lightning accident rate is controlled at a certain level.展开更多
文摘Computation grid is the infrastructure for the next generation internet. In the past five years, research ongrid technology has been thriving and grid technology has been widely adopted by a number of government organiza-tions and research institutions to establish their own large-scale resource sharing network. This paper presents a re-view of recent research on elemental grid technology. We focus on a brief overview on Grid's protocol architecture. Inthe end, we list a series of large projects to illustrate the current application situation based on the ongoing grid tech-nology and preview the tendency of grid technology in the future.
文摘针对无线传感器网络占空比MAC协议在链路或节点失效环境下易导致严重的能量浪费问题,提出了一种基于Grid Quorum的异步低占空比M AC协议-AGQ-M AC(Asynchronous Grid Quorum M AC).AGQ-M AC采用Grid Quorum组分配信道,通过动态调配Quorum比率得到了节点的最优占空比,并在邻节点发现过程中采用双前导序文抽样来监测信道状态,以减少节点唤醒时间从而达到能量高效.仿真实验结果表明,与其他占空比MAC协议相比,AGQ-MAC延长了网络生存时间,降低了网络能耗,提高了邻发现数据传输率,同时保持较低的平均邻发现延迟.
基金国家自然科学基金(the National Natural Science Foundation of China under Grant No.60673162)北京自然科学基金(the Natural ScienceFoundation of Beijing Province of China under Grant No.4073041)
基金Project supported by National Basic Research Program of China （973 Program） （2011CB209400）, National Fligh-tech Research and Developmerit Program of China （863 Program （2011AA040405）, National Natural Science Foundation of China （Ul134106）, 3551 Optics Valley Personal Plan of Wuhan East Lake High-tech Development Zone, Science and Technology Program of SGCC（SG[2009], SG[2013]）.
文摘In recent years,along with the rapid expansion of power grids,the increasing complication of grid structures,and the development of smart grids and energy technologies,the lightning protection of power grids becomes increasingly prominent.Power grids of China have acquired significant achievements on lightning protection technologies,which are reviewed in this paper.A technical route of lightning protection is introduced in detail; it allows us to find problems through detection and measurement of lightning,to analyze problems through evaluation and simulation of lightning,to solve problems through lightning protection measures,and to prevent problems through hazard risk warning of lightning.Following the route,the technical breakthroughs of these four aspects in China are presented,including the chinese lightning detection network(CLDN),natural lightning observations,lightning faults detection at transmission lines,lightning current measurements,progresses in lightning distribution maps,lightning fault replays,lightning hazard risk evaluations,and lightning simulated experiments,as well as novel lightning protection measures.The practical devices and systems corresponding to the technologies mentioned above are also introduced and discussed.Due to the progress of lightning protection technologies in recent years,despite the rapidly growing length of transmission lines in China,the lightning accident rate is controlled at a certain level.
